Venera 10, like its sister craft Venera 9, fully accomplished its mission to soft-land on Venus and return data from the surface. The spacecraft followed an identical mission to that of its twin, arriving only a few days later after two trajectory corrections on 21 June and 18 October 1975. The 660-kilogram lander separated from its parent on 23 October and entered the atmosphere two days later at 01:02 UT. During reentry, the lander survived gravity acceleration as high as 168 g and temperatures as high 12,000_C. It performed its complex landing procedures without fault and landed without incident at 02:17 UT approximately 2,200 kilometers from the Venera 9 landing site. Landing coordinates were 16_ north latitude and 291_ longitude. Venera 10 transmitted for a record 65 minutes from the surface, although it was designed to last only 30 minutes. A photo of the Venera 10 landing site showed a smoother surface than that of its twin. Like Venera 9, the Venera 10 lander was supposed to take a 360_ panorama but covered only 180_ of the surroundings because of a stuck lens cover. Meanwhile, the Venera 10 orbiter entered a 1,400 x 114,000-kilometer orbit around Venus inclined at 29_30'. Soviet officials later revealed that the termination of data reception from both Veneras 9 and 10 was not caused by the adverse surface conditions but by the flying out of view of the orbiter relays for both spacecraft. Gamma-ray spectrometer and radiation densitometer data indicated that the surface layer was akin to basalt rather than granite as hinted by the information from Venera 8.
